Project Summary. Supporting Teens? Autonomy Daily is an intervention for adolescents with ADHD that teaches compensatory skills to offset the effects of ?cool? executive functioning deficits, while teaching parents contingency management strategies to mitigate the effects of ?hot? deficits in rewards processing (Castellanos, 2006). STAND combines skills-based therapy with Motivational Interviewing (MI), designed to overcome population-specific motivational and volitional barriers to treatment uptake. Our pilot work identifies skill practice at home between session as a key malleable factor that promotes maintenance of therapeutic gains. The purpose of the current study is to empirically test the extent to which hypothesized motivational and volitional barriers interfere with treatment and whether certain therapeutic strategies can influence parent and teen barriers, and in turn, improve skill practice and long-term therapy outcome. As a result, the study aims to identify key strategies that therapists may use to improve the long-term trajectory of illness for ADHD. From 2011-2016, our team completed two RCTs of STAND?an R34 funded by NIMH that compared STAND to Treatment as Usual (R34MH092466; N=128; Sibley et al., 2016) and a Klingenstein Third Generation Foundation funded trial that compared STAND to group parent training and teen organization skills training (KTGF; N=122; Sibley et al., in preparation). In the R34 and KTGF trials, a combined total of 128 participants were assigned to receive STAND. Therapists were instructed to audio record all STAND sessions, leading to the availability of 921 recorded sessions for coding in the proposed project (M=7.1 sessions per participant). In Y01, we will work with our consultants, Dr. Ernst and Dr. Houck, to adapt a therapy coding system (Sequential Code for Observing Process Exchanges; SCOPE; Moyers & Martin, 2008) utilized in Project MATCH (Project MATCH Research Group, 1998). In adapting these MI coding systems, we will incorporate key codes relevant to the hypothesized client motivational/volitional barriers and therapist strategic responses for adolescents with ADHD and their parents. We will undergo initial psychometric testing for the adapted coding system with a randomly selected subset of tapes prior to applying it to the 921 tapes. In addition, we will thematically code audiotapes of each family?s final STAND session, as well as newly collected in-depth interviews with past participants (N=20) and their parents (N=20) to develop new hypotheses about mechanisms of long-term outcome that are yet-to-be detected. In Y02, we will continue coding and conduct analyses of coded tapes. This proposal is novel in that it: (1) represents a first effort to develop a therapy tape coding system to detect parent and teen motivational and volitional barriers in ADHD treatment, (2) will provide a first empirical test of how therapist behaviors influence parent and teen motivational and volitional factors and by extension, transfer of skills to daily life contexts and long-term ADHD symptom remission, and (3) will explore yet-to-be-identified factors that may influence long-term outcome in adolescent ADHD treatment.